| Tesis Doctorales de la Universidad de Alcalá |
| MONITORING WATER FLUXES IN COMPLEX LANDSCAPES: IMPROVING REMOTE SENSING-BASED EVAPOTRANSPIRATION MODELS FOR TREEGRASS ECOSYSTEMS | | Autor/a | Burchard Levine, Vicente Felipe | | Departamento | Geología, Geografía y Medio Ambiente | | Director/a | Martín Isabel, María del Pilar | | Directores/as | Riaño Arribas, David; Nieto Solana, Héctor | | Fecha de defensa | 28/06/2021 | | Calificación | Sobresaliente Cum Laude | | Programa | Tecnologías de la Información Geográfica (RD 99/2011) | | Mención internacional | Si | | Resumen | 10 m) were related to the poor depiction of aerodynamic characteristics using pixel averaging approaches, due to non-linear relationships between surface roughness and turbulent fluxes. The diagnosed uncertainties at both temporal (i.e., complex phenology) and spatial (i.e., tree-grass mixing) domains demonstrated the need to formulate a new model structure. To overcome these issues, a three-source energy balance (3SEB) model was proposed to inherently represent the distinct vegetation layers in TGEs. 3SEB was evaluated across four TGE experimental sites in Australia, Spain (2) and USA, with variability in climatic regimes and vegetation. 3SEB proved to be robust (root-mean-square deviation (RMSD) of ET ~60 W/m-2), improving over TSEB-2S (RMSD ~70 W/m-2) and TSEB (RMSD ~85 W/m-2) in addition to providing a framework to investigate ET partitioning from the different landscape components. These findings should help to alleviate the disproportionally large uncertainty of global remote sensing-based ET products in these important and extensive ecosystems, providing new avenues to understand the role of complex vegetation dynamics, at both temporal and spatial scales, in modulating ecosystem level fluxes and water scarcity. |
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